The present invention relates to supervising a network, that is a network of electronic components comprising, for example, workstations, personal computers, servers, hubs, routers, bridges, switches, (hereinafter referred to as components of the network), and links between these components which may be in the form of physical cable or wireless links. The network may be a local area network (LAN), wide area network (WAN) or other types and may operate in accordance with any desired protocol.
After such a network has been installed, it is desirable for the person appointed network manager to be able to understand the technical operation of the network. In known network management systems, the manner in which the relevant data is retrieved from the managed devices, compiled and displayed has been problematic in several respects. Firstly, the data received from each of the managed devices is simply compiled and displayed as a list of data for the user to interpret. Secondly, the data does not provide information about unmanaged devices. Thirdly, information about a given network device, such as the type of device, location of the device on the network and operating speed of the device, may be contained in different sections of the compiled data. Consequently, conventional systems are cumbersome and difficult to use.
In co-pending UK patent applications numbers 9910843.3, 9910844.1, 9910838.3, 9910837.5, 9910839.1, 9910840.9, (each in the name of the assignee of the present application) which are incorporated herein, we describe various arrangements for providing automatic interrogation of the network to thereby produce a network map which may be displayed on a visual display unit showing the components and links between the components. At its simplest, and where the component is a xe2x80x9cmanagedxe2x80x9d component, this is usually provided by interrogation using a known protocol, such as the SNMP protocol, of the so-called xe2x80x98agentxe2x80x99 of each component which stores the components unique MAC address, the type of component and the MAC addresses the components which are connected to the ports directly or indirectly.
However, the agent of each component can only store the MAC address of the remote component (or the port address) to which a particular port is connected after it has received a signal originating from that remote component which includes the relevant address. Data signals usually carry both source and destination addresses but until the source address is received, it cannot be stored by the agent. In particular operations of the network, source address headed data may generally only pass in one direction. Thus there will be a number of ports which will not have received a signal sourced from the remote component to which they are attached and which therefore will not know the MAC address of that remote component. As a result, it is impossible to provide a network map or deduce properly the topology of the network as it is necessary to know which ports of which component are attached to each other.
The present invention seeks to address this problem.
It should also be noted that some components (usually switches and hubs) use the component address as a source address whereas other components (such as routers) use the port address as the sourced address.
The present invention relates to use of remote poll to facilitate determining network topology.
The present invention provides a method of supervising a network, which network comprises a plurality of components having ports, at least some of which ports are connected by links to ports on other components, at least one component including an agent to ascertain the source addresses of the remote component or port to which each of its ports is connected when data is received from the relevant remote component, said method comprising:
interrogating said at least one component to establish a group of any ports which do not have the source address of the relevant remote component or its port to which they are connected by a link;
and in respect of at least one of the ports of said group, remotely polling the remote component to which it is connected via said port to cause said remote component to return to that port a signal including the address, whereby the source address of the relevant remote component or its port can be identified.
The present invention also provides network supervising apparatus for supervising a network comprising a plurality of components having ports, at least some of which ports are connected by links to ports on other components, at least one component including an agent to ascertain the source addresses of the port of the remote component or port to which each of its ports is connected when data is received from the relevant remote component, said apparatus comprising:
a processor unit which interrogates said at least one component and establishes a group of any ports which do not have the source address of the relevant remote component or its port to which they are connected by a link;
and in respect of at least one of the ports of said group, remotely polls the remote component to which it is connected via said port to cause said remote component to return to that port a signal including the address, whereby the source address of the relevant remote component or its port can be identified.
The present invention also provides a computer program on a computer readable medium or embodied in a carrier wave for use in supervising a network comprises a plurality of components having ports, at least some of which ports are connected by links to ports on other components, at least one component including as agent to ascertain the source addresses of the port of the remote component or port to which each of its ports is connected when data is received from the relevant remote component, said program comprising:
program means for interrogating said at least one component to establish a group of any ports which do not have the source address of the relevant remote component or its port to which they are connected by a link;
program means for causing, in respect of at least one of the ports of said group, remote polling of the remote component which is connected via said port to cause said remote component to return to that port a signal including the address;
and program means to thereby identify the source address of the relevant remote component or its port.
The present invention also provides a computer program embodied in a carrier wave for use in supervising a network comprises a plurality of components having ports, at least some of which ports are connected by links to ports on other components, at least one component including as agent to ascertain the source addresses of the port of the remote component or port to which each of its ports is connected when data is received from the relevant remote component, said program comprising:
program means for interrogating said at least one component to establish a group of any ports which do not have the source address of the relevant remote component or its port to which they are connected by a link;
program means for causing, in respect of at least one of the ports of said group, remote polling of the remote component which is connected via said port to cause said remote component to return to that port a signal including the address; and program means to thereby identify the source address of the relevant remote component or its port.